An inkjet head includes plural nozzles and plural actuators corresponding to the respective nozzles. The actuators are provided on a base material such as a silicon substrate. The actuators include piezoelectric elements and common electrodes and individual electrodes that apply a voltage to the piezoelectric elements. The piezoelectric elements are held between the common electrodes and the individual electrodes.
The common electrodes and the individual electrodes are electrically connected to tape carrier packages via plural conductor patterns formed on the base material. The tape carrier package is mounted with a driving circuit that drives the actuators.
When an electric field is applied from the driving circuit to the piezoelectric elements via the common electrodes and the individual electrodes, the piezoelectric elements are deformed to pressurize ink. A part of the pressurized ink is ejected from nozzles to a recording medium as ink droplets to form an image on the recording medium.
In the inkjet head including the actuators in which the piezoelectric elements are held between the common electrodes and the individual electrodes, the two kinds of electrodes are laminated in the thickness direction of the base material on the base material. Therefore, in order to electrically separate a conductor pattern connected to the common electrodes and a conductor pattern connected to the individual electrodes, it is necessary to interpose an insulating film between the conductor patterns. Therefore, an exclusive insulating film has to be formed between the conductor patterns. It is inevitable that a process for manufacturing the inkjet head is complicated.